My car had the exact same symptoms, exactly to a "T".
Your mechanic at work is right.

I went through all the same replacements as you did and it still starved.
Thats what those symptoms are, you touch the gas to accelerate and it bogs down, you lift up on the pedal and it wants to go. The pressure is all over the place, the O2 sensor is sending bogus signals to the computer and the computer is playing garbage in garbage out.

It was the fuel pump. I don't have a fuel pressure guage either but if you don't get a copious gas shower when cracking open the fuel line theres no pressure....or not enough. I could quickly fill a paper cup with fuel when my wife cranked the engine but that doesn't translate to the required pressure.

Try the fuel filter and be sure to get the check valve for it with the copper washers from FCP and a fuel pump , I got mine from autozone.

As soon as you pull the pump you'll see why.

With the new pump, when I slightly loosen a fuel line it takes 30 seconds for the fuel to stop spraying, then it open it a bit more and it sprays a bunch more.
The new pump blew the fuel return hose under the brake master cylinder too.